The present invention relates generally to a gear machine, and more particularly to a gear machine of the type that can act as a gear pump or a gear motor.
It is known to provide gear machines of this type with forced cooling and lubrication. For this purpose the prior art proposes to form the sleeves in which the shafts of the gears are journalled for rotation, with spiral grooves which communicate with the intake of the machine, so that as fluid travels to the gaps between the teeth of the gears to be conveyed by the gears, some of this fluid is branched off and travels through the spiral grooves in order to cool and lubricate the shafts and sleeves.
Another prior construction operates on the same principle, i.e. some of the incoming fluid is branched off to cool and lubricate the bearings and shafts. In that construction the passages through which this fluid travels are configurated differently from the construction mentioned above.
Both of these prior-art constructions, however, have the disadvantage that they are capable of utilizing only some of the incoming fluid, namely a very minor portion thereof, for purposes of cooling and lubrication. Because of this, these prior-art constructions do not offer particularly effective cooling and lubrication and are totally insufficient for use in high-performance machines where excellent lubrication and cooling is a necessity.